Kestrels get new nest boxes

Garry Brandenburg

The AMERICAN KESTREL (Falco sparverius) is a very small bird of prey, a falcon actually, and it is quite adept at catching small prey to make its living. Finding homes to live in has been problematic. So conservation agencies like the Marshall County Conservation Board have decided to assist. The boxes are about twelve inches square and eighteen inches deep. A three-inch diameter hole is drilled for an entrance. Permission was obtained from the County Engineer’s department to place the boxes on the back side of county road signs. Take time to watch for these boxes and the falcon that may be nearby in hovering flight mode or perched on a fence or power line.

This nest box program is several years old. Prior to 2015, 36 nest boxes had been constructed and placed in various parts of Marshall County’s secondary road system. Then in 2015, MCCB staff checked the bird apartment dwellings while in the process of installing 27 more new boxes. In the previously installed nest sites, 20 were successful for kestrels, and one was unsuccessful. In addition. other birds found the boxes to their liking. For instance, seven starlings made the boxes work for them. So did four mice and one tree swallow.

This month, checks are being made on all previously installed boxes plus 42 new boxes were added. The existing 63 boxes had evidence of 29 successful kestrel families, one wren, four starlings, four tree swallows, six bluebirds, four mice and two house sparrows. It is good to note the high level of success by the intended users, American Kestrels. May they have a good year in 2017.

Kestrels are colorful little birds, quick and agile and very sharp eyed critters. Look for two black eye lines on the face that resemble a double mustache. Body size is similar to a bluejay. Male kestrels have blue-gray wings and body plumage of tan to brown with dark flecks.

Life for kestrels is not without danger from larger raptors like the Northern Goshawk, Red-tail-hawks, Barn Owls, American Crows, Sharp-shinned Hawks and Cooper’s Hawks. In some parts of the country fire ants kill kestrels in the nest. Corn snakes and rat snakes may also crawl into nest cavities to kill and eat the bird.

Vision is acute for kestrel as one might expect. They have to be able to distinguish the tiniest of details in grassland habitats that may lead to a small rodent. Kestrels can see ultraviolet light, which shows up to the bird as bright spots left by urine trails left by voles. The bird can just follow the light paths to a potential meal. Food is eaten whole or if needed later, can be stashed in a tree cavity, grass clump, or old fence post.

A male kestrel banded in 1987 in Utah lived for 14 years and 8 months. This is a bit more than average but illustrates the possibilities if good habitat and food sources are plentiful. Short grasslands with a sparse scattering of trees is a good place to look for kestrels. Insects are important diet items that include grasshoppers, cicadas, beetles, dragonflies, scorpions, spiders, butterflies, moths, voles,, mice, shrews, bats and small songbirds. Snakes, lizards and frogs are in the list of food types.

Once on a nest site and defending the territory around it, a kestrel pair will mate and begin house duties to raise a family. Four to six eggs form a clutch with each egg about one inch wide and one point five inches long. Incubation takes 26 to 32 days. Far from being endangered or threatened status-wise, this is a very common and widespread falcon. If and when you see these little falcons this winter, spring or summer hovering over road ditch grasses, with its body facing into the wind and its wings flapping just enough to hold its hover over the hunting area, know that this bird is being assisted with new homes on the back side of road sign posts.

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TAX time computations are well underway now through April 15. Do remember to assist wildlife programs especially for non-game species via the check-off for the Fish and Wildlife Fund, line 57 on form 1040. This is a charitable contribution to deduct on next year’s taxes. So give generously. Tax preparers may not bring this check-off option to your attention, so please ask. Funds have been used in the past for Prairie Chicken restorations in southwest Iowa, for pollinator species like butterflies and bees, and endangered species surveys and monitoring.

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CHRONIC WASTING DISEASE got the full attention of a standing room only crowd of people at Elkader’s Johnson’s Reception Hall last week. The subject was this disease, shorthanded as CWD, found in a few more wild deer this past season. The meeting offered science as it is known now of causes and options for attempted control. The public got their chance to learn more and ask questions.

During 2016’s hunting seasons, a wild free-ranging deer was taken in west central Clayton County. This deer tested positive for CWD, the first case outside of other known positive deer tests from Allamakee County over the past several years. Wisconsin had an outbreak of CWD beginning in 2001. Deer have been found in southeast Minnesota with positive test results. It is entirely possible that the slow and what appears to be steady spread of this disease westward into more Iowa counties.

CWD is a misshapen protein called a prion. A deer’s body cannot recognize it as a foreign substance so no antibodies are produced to fight it. The disease is spread from animal to animal through nose to nose contact, and contamination or urine, feces and saliva from deer carrying the disease. Researchers have noted it is nearly impossible to kill the prion.

The disease in infected deer is always fatal. Deer do not show outward symptoms until the disease is well along its course of deterioration. A health looking deer can carry chronic wasting disease from 16 months to three years before clinical signs show themselves. There is just no good news to report on this subject.

If wildlife managers and the deer hunting public do nothing to combat its spread, it will continue to spread. So one course of action is for hunters to take more adult deer (population downsizing) via a special season that began Feb. 18 and will run through Marsh 5 in a 10-mile radius of western Clayton County. Iowa DNR biologists hope to collect samples from 250-300 deer during that time. Tissue samples will be obtained and sent to a lab for CWD determination. Return data takes anywhere from several days to two to three weeks. That data collection will be critical to future management scenarios this fall in northeast Iowa.

Hunters will be required to get a Scientific Collectors Permit and tags. Then if a deer is killed, contact a DNR officer within 24 hours to arrange for tissue sample collection. There is no charge for the science collector permit or the special deer tags to be issued. Hunters will be almost entirely on private lands, may use shotguns, muzzle loaders, rifles of caliber .24 or larger or archery equipment. All hunters regardless of weapon must wear blaze orange. Participation in this special hunt is voluntary.

Other methods to slow the advance of CWD is to not use piles of feed or salt to attract deer. These baited sites tend to concentrate deer and may facilitate nose to nose contact by deer. Deer bone carcasses should also be not left to decay into the soil. Best practice in this case is to place all contents in large heavy duty plastic bags for burial at a local approved landfill.

Iowa began testing for CWD in 2002 after it was discovered in Wisconsin. Iowa has tested over 61,000 wild deer since then plus an additional 4,000 samples from game farm deer. CWD is an important issue in Iowa and all of our surrounding states. According to a Minnesota’s Outdoor News story dated Jan. 27, Michelle Carstensen, DNR wildlife health program supervisor, thinks the problem of CWD in southeast Minnesota is not the result of “natural deer movement.” She has good reasons to believe that some people are moving deer from captive herds to other areas. This is contributing to the problem. One deer farm facility in northeast Iowa had an infection rate of about 80 percent for its deer inside its fences. That was several years ago. Contaminated soils still hold the disease vectors for decades.

Chronic Wasting Disease is an issue that will not go away, will require due diligence by all landowners and deer hunters, and a long range testing program to monitor for the disease and its potential spreading to other areas. That is the reality of the situation.

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Did you know? … that the Iowa record for the most snow in one day was April 20, 1918 in and around the city of Lenox. Twenty-four inches of snow fell that day. This reminder is brought to you by the weather records of Mother Nature. She likes to surprise us humans periodically with stuff like this. So do not think Spring-like weather is going to last forever during February. We all have a lot winter to endure and it can be brutal.

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Garry Brandenburg is a graduate of Iowa State University with BS degree in Fish & Wildlife Biology. He is the retired director of the Marshall County Conservation Board. Contact him at P.O. Box 96, Albion, IA 50005.